The genus Scorpio Linnaeus, 1758 (Scorpionidae) was for most of the last century known to have only one species, Scorpio maurus Linnaeus, 1758, which has an impressing distribution ranging from most of North Africa to the eastern parts of the Middle East.
In the last decades it became clear that Scorpio maurus was a species complex with many hidden species, and today the genus consists of 24 species. However, the taxonomical and phylogentic situation of the genus is challenging, especially because of the lack of reliable morphological characters to distinguish the species and subspecies. Also, several new species have been described without genetic analysis confirming the species status.
Manel Khammassi and co-workers have recently published a study with the aim of the present study to analyze the phylogenetic relationships and the evolutionary events that promoted diversification within the genus Scorpio. The study revealed twenty distinct lineages forming two geographically separate clades, a Maghrebian clade and a Middle Eastern clade. Most named species were found within the lineages, but additional lineages found are indicating potential new, unnamed species.
Abstract:
The burrowing scorpions of the genus Scorpio Linnaeus, 1758 were considered to be a single polymorphic species, Scorpio maurus Linnaeus, 1758, distributed from West Africa across the Sahel and the Saharan highlands through the Maghreb and the Middle East, to Iran. After various revisions, the complex was treated as including 18 species and seven subspecies. Five additional new Scorpio species were recently described. However, doubts remain regarding the validity of these taxa due to the lack of reliable characters and the lack of genetic data for many species. The aim of the present study was to analyze the phylogenetic relationships and the evolutionary events that promoted diversification within the genus. Phylogenetic analyses were performed using 633 base pairs of the mitochondrial COI gene from 51 individuals collected in Tunisia, Morocco, and Egypt, combined with 74 previously published sequence data. Phylogenetic analyses revealed twenty distinct lineages forming two geographically separate clades, a Maghrebian clade and a Middle Eastern clade. Although most named species formed distinct lineages, various additional lineages were identified, highlighting potential unnamed species. Divergence time estimates indicate that the division within the genus Scorpio began during the Mid-Miocene, a period characterized by tectonic events coupled with climatic oscillations. Further differentiation occurred during the Miocene-Pliocene transition when climatic fluctuations resumed and the Mediterranean became increasingly arid. Speciation within the genus Scorpio may have been driven by the expansion of the savannas and Sahara Desert, the associated reduction of a once widespread rainforest into numerous micro-refugia in the mountains of the Mediterranean region, and by adaptation to these new habitats
Reference:
Khammassi M, Nouira S, Badry A, Sadine SE, Harris DJ. Phylogeography and evolutionary history of the burrowing scorpion genus Scorpio Linnaeus, 1758 (Scorpiones: Scorpionidae) in the Mediterranean Basin. Organisms Diversity & Evolution. 2024:1-18. [Subscritpion required for full text]
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